This invention relates to minimum tillage planting of seeds, which is desirable for erosion control as well as planting efficiency. Its usage permits the planting of a field in one pass and without the field preparation normally required when making use of conventional plowing and cultivating methods. The apparatus is designed specifically for use in fields which have been previously cultivated, planted and harvested where the stubble of the earlier crop has been left in the field for erosion control. It permits planting of a field with minimum disturbance of the soil, the seeds being located in tilled furrows separated transversely by strips of untilled soil. Because the apparatus leaves a substantial portion of the field untouched, strips of untilled soil and stubble are alternated with the planted areas to assure better erosion control. This is of particular value in areas where crops such as wheat are grown on side hills. Another advantage of the apparatus is that it does not result in soil movement to one side or ther other, as is the case with moldboard plows. It enables the user to plant seed with a minimum amount of soil disturbance.
More importantly, this apparatus permits planting and fertilizing of a field in a single pass. This is accomplished by a combination of chisels, cover rollers and grain drill components aligned longitudinally on a single framework, together with a fertilizer application system which directs liquid fertilizer to the lower end of each chisel. The end result of each pass of the machine is a tilled furrow having a layer of fertilizer at one elevation, a cover layer of soil, and a layer of seeds at a second elevation above the fertilizer. In this manner, fertilizer is immediately available to the germinating seeds, which have been protected from fertilizer damage or "burning" by the soil cover between the two layers.
Planting machines have been proposed and built which plant seeds in untilled ground. Such "no-till" methods have met with only limited acceptance. A substantial problem has been a toxic affect of the straw or stubble on new plants when seeded directly into the stubble. It appears that some cultivation is desirable for proper new plant growth.
The present apparatus has principal application in the planting of fall or winter wheat, which is planted in the fall and experiences substantial growth the following spring. When a field is fully cultivated before planting of wheat in the fall, the wheat plants do not experience sufficient growth to anchor the surrounding soil during the wet winter and early spring seasons. This is a particular problem where the planted area experiences an accumulation of snow on frozen soil, followed by warm winds and rain. This frequently results in high runoffs on the unprotected soil and substantial erosion damage to the crop and field.
The machine described herein was developed by assimilating several successful practices in growing wheat under such conditions. First, the best conservation tillage practices call for increased use of a chisel plow rather than a moldboard. The chisel plow has the advantage of causing the least soil disturbance, and eliminates the sideward displacement of soil which is a necessary result of using conventional moldboard plows. Secondly, fall application of fertilizer is advocated as a cost effective practice. It provides fertilizer to the germinating plants from the very beginning and increases fall growth of winter wheat. Finally, fluted-feed, end wheel drills are almost universally used in planting wheat in the fields in which these growing conditions are experienced, particularly on hillsides.
From these known practices was developed the minimum tillage planter described herein, specifically for seeding of fall wheat. It is a single pass--from stubble to planted field planter. It is not a "no-till" machine because it has chisel points and packer wheels which break up the soil and clear a path ahead of the planting mechanism. It provides efficient planting and is a significant factor in reducing erosion. Liquid fertilizer is metered into the furrow at the bottom of the chisel points and below the level at which seed is planted. The purpose of the chisel points is not for deep chiseling, but to clear the field residue and help to provide a seed bed.